This invention relates to network management tools for managing distributed networks and, in particular, to alarm management and alarm servicing tools.
Present day telecommunications and information networks have become larger and far more complex than those which have been available only a few years ago. The trend towards increases in size and complexity can be expected to continue at a high rate into the foreseeable future with the proliferation of cellular networks, the development and deployment of global satellite networks, and the expansion of basic wireline networks in developing nations. Both homogeneous and heterogeneous networks are now being connected together by means of the Internet and other inter-network connection mechanisms.
In order to maintain network reliability and an acceptable quality of service, it is necessary to carefully monitor and manage network resources. However, as existing networks grow larger and more complex, network management also becomes more difficult and more complex. The prior art responded by providing automated management tools for reporting network status. These tools allowed network management personnel to improve the quality of service and maintain high network availability and reliability.
Such automated management tools were distributed and generally arranged as client server applications which provided integrated systems for supporting heterogeneous network environments. The client portion of the tools was arranged to have a standard interface which minimized variations of look and feel of the system as seen by the network operations personnel whereas the server portion was designed to operate on different platforms. The distributed architecture allowed the tool to evolve and scale as the networks evolved in size, capabilities, and geographies.
One such distributed network management tool is the Solstice Enterprise Manager(trademark) (Solstice EM) network management system which was developed and is marketed by Sun Microsystems, Inc. This tool has an object-oriented and distributed architecture which consists of a plurality of cooperating components, including applications, libraries, information services, databases, and protocols, each of which performs specific tasks. The managed resources are arranged as a plurality of interconnected nodes and xe2x80x9cmanagement agentsxe2x80x9d running in each node gather information about the resources associated with the node. The information is then forwarded back to a management information server (MIS) which interacts with management applications running in other nodes. The MIS can request and change management parameter values, perform requested actions, and receive and evaluate problem reports (e.g. events, such as SNMP traps and CMIP notifications) that the management agents generate.
Although the MIS and the management agents can communicate with each other via various network management protocols such as Simple Network Management Protocol(SNMP), Common Management Information Protocol (CMIP), or other proprietary/legacy protocols, the Solstice EM(trademark) framework interposes software model representations of managed resources in the MIS between management applications and agents of managed resources. The result is that the management applications need not be concerned with management protocol dependencies of the managed resources since the applications only interact with the software model representations in the MIS.
In particular, the management applications direct management tasks in the MIS via a xe2x80x9cPortable Management Interface (PMI)xe2x80x9d which is a high-level abstraction of an interface for manipulating objects, regardless of their class description, supported protocol, or location. The PMI is also used by the MIS to communicate with the management agents. For example, the MIS can use a management protocol adapter (MPA) to communicate with a management agent. An MPA translates MIS requests to protocol-specific primitives (e.g. CMIP, SNMP, RPC, or other proprietary/legacy protocol primitives) depending upon the management agent in question. For example, a CMIP MPA communicates with CMIP agents.
One of the most important tasks that a network manager can perform is xe2x80x9calarmxe2x80x9d monitoring and management. An alarm is an unsolicited notification called a xe2x80x9ctrapxe2x80x9d in SNMP terminology and an xe2x80x9ceventxe2x80x9d in CMIP terminology which is generated by an agent and sent to the MIS. The notification generally indicates that a particular managed resource associated with the agent has experienced a fault or failure condition or otherwise requires attention. Alarms have an associated severity level which can range from xe2x80x9ccriticalxe2x80x9d to xe2x80x9cwarning.xe2x80x9d Network management personnel can manage the alarms by changing their state. For example, a newly generated alarm has an xe2x80x9copenxe2x80x9d state. Network management personnel can xe2x80x9cacknowledgexe2x80x9d the alarm indicating that the alarm has been noted. After investigating the problem, the alarm can be xe2x80x9cclearedxe2x80x9d, indicating the problem has been corrected.
Alarm Services is a module in the Solstice EM(trademark) MIS responsible for updating and storing the state of managed objects in the MIS. Alarms arrive at the MIS as event notifications (via an MPA, for example). When such an event is received by the MIS, it is stored in an alarm log as an alarm log record by a Logging Services module and the Alarm Services module is informed about the arrival of this alarm. The Alarm Services module maps each managed-object-based alarm to a corresponding node in a topology database (discussed below) and updates the alarm counters for that topology node based on the alarm severity. The Alarm Services module also keeps the severity synchronized so that it represents the highest (most critical) uncleared alarm log record that is posted against the topology node. The node status is propagated to applications like the Solstice EM(trademark) Viewer and displayed in the appropriate color. The alarm information is also sent to the Solstice EM(trademark) Alarm Manager application for display.
The Solstice EM(trademark) system provides logging services, whereby all network events of interest can be logged in the system. Event logs (also referred to as xe2x80x9clogsxe2x80x9d) maintain a record of the information provided in event notifications. Each log can be configured to select the event notification information that should be recorded in the log. An MIS can contain multiple logs, each containing a different configuration in order to record different types of information (corresponding to different events) in separate logs. Each log is a local managed object. A log contains event log records which mirror information in the event notifications. If a new notification is added to the MIS, a new event log record managed object class that corresponds to the new notification type is also added.
The Solstice EM(trademark) system also maintains a topology database which represents the managed objects. Topology nodes are an important part of the topology database and are created by users to logically model managed objects. Each topology node has pointer(s) to the managed object(s) it represents. These managed objects can be SNMP managed objects, RPC managed resources running proprietary/legacy management protocol agents, or any object. A topology node can also represent multiple managed objects. Topology Services is a module in the MIS that provides topology database functions that can be accessed via the PMI.
While distributed client server network management systems operate well, they have some drawbacks. For example, the client portion of such systems was generally platform dependent. Therefore different client versions were necessary to allow the management operations to be performed from different locations. Further, much of the information, such as events, were forwarded back to the client application and cached in the client application for later review. Therefore, the computer system running the client application had to have significant memory and computing power. Consequently, it was often not possible for network personnel to monitor or manage a network from a convenient location, such as their home.
The aforementioned drawbacks are addressed in one illustrative embodiment of the invention in which the client portion of a distributed client-server network management system uses an interface designed with, and written in, a platform independent language, such as Java. This allows management application programs to be written in the platform independent language and insures their portability.
Further, in accordance with another aspect of the invention, the inventive interface allows a user to query the alarm log while the alarm log record information is cached at the server so that only a small client program is necessary. This program can run on a system with minimal resources, thereby allowing a network manager to manage a network from virtually any location on the network. For example, the client management application could be written as a Java applet which could then be run on any Java-enabled browser.
In accordance with still another aspect of the invention, an alarm log can be queried on any user-defined attribute based on relational criteria such as: xe2x80x9cgreater thanxe2x80x9d, xe2x80x9cless thanxe2x80x9d, xe2x80x9cequalxe2x80x9d, xe2x80x9cnot equalxe2x80x9d, etc.